The invention relates in general to gear hinges and, more particularly to a gear hinge that contains an electrical conductor so that an electrical circuit may be completed through the hinge.
Continuous gear hinges will tolerate considerably more abuse than more traditional knuckle hinges and for that reason are found on doors which see substantial use, such as those at the main entrances to schools and public buildings, often as replacements for knuckle hinges. The typical gear hinge has two leaves, each provided with a gear segment. The gear segments of the two leaves mesh while being held together with a cap that extends over and behind them. The one leaf is attached to the door that the hinge supports while the other is secured to the hinge jamb of the door frame out of which the door opens. Both leaves extend the full length of the door, thus providing multiple locations at which to attach the hinge to the door and hinge jamb. Knuckle-type hinges, on the contrary, secure the door to the hinge jamb at small isolated areas, and may pull away from one or the other or both, particularly when used on doors that see heavy or abusive use.
More and more doors carry electrically-operated appliances such as locks or sensors, and these appliances require electrical service in the doors themselves. And this holds particularly true for the very same doors on which continuous gear hinges are well-suited. A variety of designs exist for transferring electricity through knuckle hinges. In this regard, see U.S. Pat. Nos. 3,838,234; 3,842,386; and 4,412,711. However, continuous gear hinges have seen little innovation in this respect.